Microgravity Science and Technology最新文献_第6页

Friction Properties of Journal-bearing-like Conformal Contacts in Microgravity Environment 微重力环境下类似滑动轴承的共形接触的摩擦特性

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-02-16 DOI: 10.1007/s12217-024-10096-x

Shujia Wan, Bing Han, Li He, Ruiting Tong, Jingyan Wang, Baobao Qiang, Menghe Zhou

{"title":"Friction Properties of Journal-bearing-like Conformal Contacts in Microgravity Environment","authors":"Shujia Wan, Bing Han, Li He, Ruiting Tong, Jingyan Wang, Baobao Qiang, Menghe Zhou","doi":"10.1007/s12217-024-10096-x","DOIUrl":"10.1007/s12217-024-10096-x","url":null,"abstract":"<div><p>Friction is a primary failure mode in micro-nano electromechanical systems due to the high surface-to-volume ratio. Microgravity further complicates this issue in journal-bearing-like conformal contacts by promoting irregular disturbances. This paper aims to gain insights into the anti-friction design of journal-bearing-like devices through molecular dynamics simulation. A molecular dynamics model was proposed and the calculation method of the friction force was derived. In the absence of disturbance, the proposed model was compared with a non-conformal model which unfolded the bearing as a plane, and the influence of initial radial clearance and axis inclination on the friction force was investigated. The results showed that the proposed model could present more accurate friction forces than the non-conformal model. The friction force was inversely proportional to the initial clearance, and the axis inclination could reduce the friction force. Regarding disturbances as the superposition of two vibrations perpendicular to each other, in which case the trajectory of the journal was a Lissajous curve, the effects of frequency, stiffness coefficient, amplitude ratio, and frequency ratio were investigated. The results showed that the average friction force increased with the rising frequency in the range of 0.8 ~ 4.8 GHz, then decreased with the further increase of frequency. The average friction force was lowered when the stiffness coefficient increased from 100N/m to 1000N/m. For two representative frequencies, the average friction force exhibited different trends with the amplitude ratio. Except for the case of 1.25, increasing the frequency ratio could reduce the friction force. It seemed that applying a well-designed Lissajous route was a promising way to reduce friction.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Profiles of free Surfaces in Revolved Containers Under Microgravity 微重力下旋转容器中自由表面的轮廓

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-02-15 DOI: 10.1007/s12217-023-10093-6

Shuyang Chen, Li Duan, Wen Li, Shangtong Chen, Qi Kang

{"title":"Profiles of free Surfaces in Revolved Containers Under Microgravity","authors":"Shuyang Chen, Li Duan, Wen Li, Shangtong Chen, Qi Kang","doi":"10.1007/s12217-023-10093-6","DOIUrl":"10.1007/s12217-023-10093-6","url":null,"abstract":"<div><p>Nowadays a propellant residual gauging method based on the thermal response of the tanks’ wall is developed. And the liquid distribution and meniscus height have great effects on the thermal response. Profiles of liquid free surfaces in revolved containers under microgravity are studied through theoretical analysis and numerical simulation in this paper. The analytical formula for the static profile of the liquid surface in the spherical tank is established. It shows that the profile is a section of a circle cut off by the tank wall. For given the geometry of the tank, liquid volume and contact angle, the profile of the free surfaces under microgravity can be obtained by using the Shooting method based on the theoretical model. Numerical simulation is carried out with the Volume of Fluid method, and it is verified that the static profiles at different contact angles and liquid filling rates fit the theoretical descriptions. It is concluded that the meniscus height increases slowly as the filling rate increases, and the smaller the contact angle, the more obvious this trend. Then the theory is extended to the tanks of arbitrary shapes, and the critical position of the profile is derived. Below the critical position the propellant may accumulate in some corners or pits, which makes it unable to be fully utilized. The critical position is related to the shape of the tank and the contact angle. This research is of great value for the prediction of the static profiles of liquid surfaces in tanks and the propellant residual gauging.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stability of One-Dimensional Vertical Flow Through a Porous Domain Under Pumping of a Finite Volume of Impurity 在抽吸有限体积杂质的情况下，一维垂直流经多孔域的稳定性

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-02-15 DOI: 10.1007/s12217-023-10089-2

Boris S. Maryshev, Lyudmila S. Klimenko, Nikolay V. Kolchanov

引用次数: 0

Pressure Drop Predicting Model for Gas and Oil-Based Drilling Fluid Two Phase Flow in Vertical Annulus 垂直环空天然气和石油钻井液两相流压降预测模型

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-24 DOI: 10.1007/s12217-023-10090-9

Bangtang Yin, Tianbao Ding, Xuxin Zhang, Zhiyuan Wang, Baojiang Sun

{"title":"Pressure Drop Predicting Model for Gas and Oil-Based Drilling Fluid Two Phase Flow in Vertical Annulus","authors":"Bangtang Yin, Tianbao Ding, Xuxin Zhang, Zhiyuan Wang, Baojiang Sun","doi":"10.1007/s12217-023-10090-9","DOIUrl":"10.1007/s12217-023-10090-9","url":null,"abstract":"<div><p>Blowout is among catastrophic accidents in oil and gas drilling, and it is caused by abnormal pressure resulted from gas kick from reservoir which cannot be prevented due to limits of drilling technology. Accurate prediction of wellbore pressure is an effective method to prevent blowout. Based on electrical capacitance volume tomography (ECVT), the experiments of gas and white oil two-phase flow with viscosity of 16 mPa·s, 23 mPa·s, 26 mPa·s and 39 mPa·s in vertical annulus are carried, and the pressure drop in vertical annulus is tested. Considering the influence of viscosity, modification of the friction loss coefficient and prediction of the pressure gradient in bubble flow, slug flow and churn flow are studied. The prediction accuracy of the modified model is compared with the pressure gradient model established in the Caetano’s experiment (air-kerosene, ID 42.2 mm and OD 76.2 mm). The results show that under the Caetano’s experimental conditions and the experimental conditions of this experiment, the maximum error and the prediction mean absolute error of the pressure gradient model with the corrected friction loss coefficient are lower than those of Caetano’s model.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dissipation Behaviors of Vibrated Granular Balls in Different Gravity Environments 不同重力环境下振动颗粒球的耗散行为

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-24 DOI: 10.1007/s12217-024-10097-w

Kai Zhang, Meng Chen, Farong Kou, Wenzhe Li

引用次数: 0

Phase Separation through Screen Channel Liquid Acquisition Devices in Microgravity 在微重力条件下通过筛道液体采集装置进行相分离

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-22 DOI: 10.1007/s12217-023-10085-6

Prithvi Shukla, Michael E. Dreyer

{"title":"Phase Separation through Screen Channel Liquid Acquisition Devices in Microgravity","authors":"Prithvi Shukla, Michael E. Dreyer","doi":"10.1007/s12217-023-10085-6","DOIUrl":"10.1007/s12217-023-10085-6","url":null,"abstract":"<div><p>To enable future deep space exploration, orbital refueling of spacecraft is essential. However, transferring liquid in a microgravity environment is a complex process dependent on various factors. One of the basic and critical tasks is to separate phases to allow the supply of gas-free liquid from one tank to another. For this purpose, a liquid acquisition device is essential. In this work, a screen channel liquid acquisition device was designed and used to investigate phase separation and liquid removal from an experiment tank in a microgravity environment. The experiments were performed using the drop tower facility at the University of Bremen, with HFE-7500 as the test liquid under isothermal conditions. This investigation explored the interdependent effects of various phenomena, including the reorientation of liquid in the tank, capillary rise between parallel plates, flow through screen pressure variation, and bubble point breakthrough. Under subcritical conditions, the SC-LAD was found to supply gas-free liquid at the outlet, as long as the pressure drop across the screen was lower than the bubble point threshold. At the critical point, the screen started to ingest bubbles, resulting in a sharp peak in the differential pressure signal. The wetted area of the screen was obtained by analyzing images captured with a high-speed camera and used to calculate the analytical pressure drop. The experimental results were compared with the analytical solution and discussed in detail.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12217-023-10085-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Collision Behaviors of Two Successive Compound Droplets in an Abrupt Expansion Microchannel 突然膨胀微通道中两个连续复合液滴的碰撞行为

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-20 DOI: 10.1007/s12217-023-10095-4

Nang X. Ho, Hung V. Vu, Truong V. Vu

{"title":"Collision Behaviors of Two Successive Compound Droplets in an Abrupt Expansion Microchannel","authors":"Nang X. Ho, Hung V. Vu, Truong V. Vu","doi":"10.1007/s12217-023-10095-4","DOIUrl":"10.1007/s12217-023-10095-4","url":null,"abstract":"<div><p>In the present paper, merging of two successive compound droplets in an abrupt expansion microchannel using direct numerical simulations is presented. The compound droplets undergo deformation and velocity decreases when entering the expansion region. Their interaction behaviors are divided into two modes of merging and non-merging. These two modes are dominated, and influenced by fluid dynamic parameters, compound droplets’ center distance, the expansion ratio of microchannels and the size of compound droplets, which are analyzed through the results of numerical simulation. The capillary number, the fluid viscosity, and the droplets’ distance increase lead to the merging time of the droplets increases. Although increasing the inner interfacial tension does not significantly affect the merging time of two outer droplets, it significantly reduces the merging time of two inner droplets. Meanwhile, varying the expansion ratio and the droplet size results in the transition between the two interaction modes. Two diagrams for the mode transition, based on the capillary number, the droplet center separation, and the droplet size are also given.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139510329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on Ground Microgravity Simulation System Based on Parallel Mechanism 基于并行机制的地面微重力模拟系统研究

IF 1.3 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-20 DOI: 10.1007/s12217-023-10094-5

Jiaxi Jin, Xuan Sun, Dong Yu, Zhaobo Chen

{"title":"Research on Ground Microgravity Simulation System Based on Parallel Mechanism","authors":"Jiaxi Jin, Xuan Sun, Dong Yu, Zhaobo Chen","doi":"10.1007/s12217-023-10094-5","DOIUrl":"10.1007/s12217-023-10094-5","url":null,"abstract":"<div><p>This paper presents a reconfigurable satellite ground microgravity simulation system based on a parallel mechanism, which allows cxsfor adjustable gravity coefficients and can simulate three-dimensional space movement with fast response and high accuracy. Firstly, the parallel motion platform and parallel six-dimensional force sensor designed specifically for the microgravity simulation system serve as the mechanical structure of the system. Secondly, a control system for simulating microgravity has been proposed, which includes a data acquisition component and a motion control component. Thirdly, a novel microgravity simulation algorithm, which can adjust the gravity coefficient and is based on the constant variation method, was proposed to establish the mapping relationship between the six-dimensional external force and displacement. Finally, the six-dimensional force sensor is statically calibrated and demonstrated excellent measurement performance. After implementing gravity compensation through surface polynomial fitting, the motion platform for microgravity simulation can react within 0.15 s upon detection of a force signal by the sensor, with a response error of less than 3%. The ground microgravity simulation system based on parallel mechanisms has been successfully applied to test the tolerance capability of reconfigurable satellite docking interfaces.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139507664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Investigation on Dynamic Characteristics of Highly Viscous Droplets and Liquid Bridges Under the Influence of Electric Fields 电场影响下高粘性液滴和液桥动态特性的实验研究

IF 1.8 4区工程技术

Microgravity Science and Technology Pub Date : 2024-01-10 DOI: 10.1007/s12217-023-10091-8

Shuo Su, Tai Wang, Xiaolong Ma, Zhaojiu Zhang, Chuntao Liu

{"title":"Experimental Investigation on Dynamic Characteristics of Highly Viscous Droplets and Liquid Bridges Under the Influence of Electric Fields","authors":"Shuo Su, Tai Wang, Xiaolong Ma, Zhaojiu Zhang, Chuntao Liu","doi":"10.1007/s12217-023-10091-8","DOIUrl":"10.1007/s12217-023-10091-8","url":null,"abstract":"<div><p>Formation of highly viscous droplets and liquid bridges under the influence of electric fields is widely used in material preparation, food processing, inkjet printing and 3D (three-dimensional) printing. To investigate the formation of droplets and liquid bridges, a visual experimental platform is designed and constructed. A non-uniform electric field is constructed using a metal capillary and a copper pole plate. By varying the voltage, capillary diameter and liquid volume flow rate, the formation of silicone oil droplets and liquid bridges is investigated. The influence of electric forces to the coiling effect of viscous fluids is researched, which has not been thoroughly investigated in previous research. The results verify that at low volume flow rates and small pipe diameters, the silicone oil formation pattern is in the droplet state. As the voltage increases, the droplet formation period decreases. When the voltage is gradually increased at higher volume flow rates, the silicone oil changes from the initial liquid bridge to the droplet. This experimental phenomenon demonstrates that the electric field can alter the instability of the jet. In the case of small volume flow rates and large pipe diameter, the droplet formation state changes from droplet mode to multi-strand jet mode after the voltage is increased to a certain level. At large pipe diameters and large volume flows rates, the liquid bridge mode with a rope coiling effect occurs due to the highly viscous nature of the silicone oil, but the rope coiling effect disappears after a certain voltage is applied.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139410438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Gravity Orientation on Flickering Characteristics of Premixed Conical Flame 重力方向对预混合锥形火焰闪烁特性的影响

IF 1.8 4区工程技术

Microgravity Science and Technology Pub Date : 2023-12-29 DOI: 10.1007/s12217-023-10088-3

Chenghao Qian, Yao Yang, Gaofeng Wang, Anastasia Krikunova, Keqi Hu

{"title":"Effect of Gravity Orientation on Flickering Characteristics of Premixed Conical Flame","authors":"Chenghao Qian, Yao Yang, Gaofeng Wang, Anastasia Krikunova, Keqi Hu","doi":"10.1007/s12217-023-10088-3","DOIUrl":"10.1007/s12217-023-10088-3","url":null,"abstract":"<div><p>Experimental and numerical simulation methods were employed to investigate the effect of gravity orientation on the dynamics of premixed conical flames. The study focused on a typical propane-air flame established on a Bunsen burner, under normal gravity (+ g), reverse gravity (-g), and transverse gravity (⊥g). In the initial phase of the research, flame shapes were examined using flame chemiluminescence imaging. Result shows that gravity orientation has a slight impact on the flame height, and buoyancy caused flame asymmetry in ⊥g case is first discovered. In addition, flame flickering frequencies were collected through heat release signal experiments, and a wide range of data is acquired. Though being affected by the same pattern by equivalence ratio and Reynolds number, the frequencies in ⊥g case are generally lower than those in + g case. Based on this, the research also obtained the new empirical correlation for ⊥g case. For clearer explanations of the flame behavior under different gravity orientations, velocity fields were visualization using Particle Image Velocimetry (PIV) experiments and Direct Numerical Simulation (DNS). Results indicated that the gravity orientation mainly influences the flame through effects on shear layer between ambient air and burnt gas, which cause different forms of K-H instability and vortex shedding motions.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139061329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0